If you're a Windows user, and even if you're not, Microsoft's SkyDrive is a great option to get onto your systems.
Microsoft currently offers 25GB of storage for free, making it a good place to get yourself some nice cloud storage. Especially if you have yet to send your most prized family photos into online storage for safe keeping.
Windows users can easily set-up folders to be automatically synced to SkyDrive, and folder sharing with other users is a breeze.
Plus there are mobile apps for Windows Phone, iPhone and Android. So you will have everything stored in your SkyDrive available to you wherever you need to access it.